Automated steel section rolling control system and method for operating same

ABSTRACT

Automated control system for a steel rolling operation which comprises the cooperation of a means for calculating the steel rolling temperature, a means for preparing a pass schedule for the rolling based upon the temperature calculated, a means for setting up a roll pass in each individual rolling pursuant to the schedule prepared, and a means for effecting the rolling of the steel rolling section.

United States Patent Kamogawa et al.

[ May 28, 1974 Filed:

AUTOMATED STEEL SECTION ROLLING CONTROL SYSTEM AND METHOD FOR OPERATING SAME Inventors: Yoshiro Kaniogawa, Sakai; Takao Tuchiya, Osaka-fu, both of Japan Assignee: Nippon Steel Corporation, Tokyo,

Japan Dec. 11, 1972 Appl. No.: 314,263

Foreign Application Priority Data Decyl 1, [971 Japan 46-99846 Dec. 11, 1971 Japan 46-99847 Dec. 11, 1971 'Japan. 46-99848 us. Cl. 72/13 Int. Cl B2lb 37/10 Field of Search 72/6-9, l0,

72/l2, l3, I9

[56] References Cited UNITED STATES PATENTS 3,253,438 5/1966 Stringer 72/12 3,540,248 ll/l970 Hostetter et al.. 72/8 3,628,358 12/1971 Fapiano 72/l9 X Primary Examiner-Milton S. Mehr [5 7] ABSTRACT Automated control system for a steel rolling operation which comprises the cooperation of a means for calculating the steel rolling temperature, a means for preparing a pass schedule for the rolling based upon the temperature calculated, a means for setting up a roll pass in each individual rolling pursuant to the schedule prepared, anda means for effecting'the rolling of the steel rolling section.

10 Claims, 21 Drawing Figures PATENTEDIAY 28 m4 331 2,693

' sum 5 0f 8 r FIGQII:

YES

AUTOMATED STEEL SECTION ROLLING CONTROL SYSTEM AND METHOD FOR OPERATING SAME BACKGROUND OF THE INVENTION The present invention relates to an automated steel section rolling control system.

In the rolling of a plate, such as a hot strip steel member or a cold strip steel member, the so-called automatic gain controller for plate control is extensively known. For instance, there is presently available means that control the thickness of the plate by the employment of a load cell for a hot reversible roller and that control the thickness by conducting the control of the tensile strength of the final stand, as well as the control of the screwdown of respective stands by the employment of an X-ray thickness gauge, a load cell, a width gauge and a looper for a cold or hot continuous mill.

However, these prior art devices control the thickness of such a-plate member that is rolled primarily under the stress applied along-asingleaxis and none has been thus far made available for an automatic rolling controller of the output gauge in the universal rolling of such steel sections, includingH-steel sections, having a complicated stateof stress appliedalong multiple axes. Explanation will be .given hereinafter with regard to an H-steelsection specifically selected as a typical steel section.

Conventionally,.it has been a general practice that the rolling pass schedule for an H-steel section is established on a trial-and-e'rror basis simply depending on the skill and intuition of an operator accumulated through his long experience. It is attributable to the fact that, in the case of rolling of an H-steel section, unlike the case of rolling of the plate-like rolling of a hoop, there is such a complicated requirement that the. web and the flange have tobe elongated as one entity, as elucidated in details below, whereas in reality the web and the flange are reduced separately and independently on respective draft percentages. Generally, with regard to a steel section rolling mill, respective passes are established by way of either manual operation or a reduction position selector in pursuance to such a reduction schedule as is standardized in advance for each and every size of finished product. The raw materials are worked and formed to the desired output gauge by reciprocating a member to be rolled thereon as often as several times or more thanten times. However, respective parts of the member to be thus rolled, after being fed through the rolling .mill, are different from one another in the temperature thereof, the web and the flange among othershave different distribution of temperature, respectively,- As the rolling does not remain the same, it is frequently the case that the output gauge cannot be maintained to have-a target value in such rolling operation as is true tothe reduction schedule standardized for respective sizes, due to. the deviation in the rigidity of the mill.

Hitherto, in such a case as this, it has been conventional that a roll operator maintains the output gauge of respective parts of an H-steel section by properly correcting the standard pass schedule by manual operation. The balance of elongation is takeninto consideration, by the result of measurement of samples taken in thefollowing processes, and the result of measurement was required for effecting the proper correction in a quick manner while exercising meticulous caution to keep a proper balance of elongation of respective parts of an I-I-steel section. The correction was subjected to individual differences and the rolling efficiency deteriorated, when the standard pass schedule had to be corrected through manual operation by a rolling mill operator, in case the result of sampling in the following process or the result of measurement thereof by the employment of a thickness gauge and a width gauge proved that the target output gauge hadnot been obtained.

SUMMARYOF THE lNVENTlON The primary purpose of the present invention lies in providing an automated steel section rolling control system that is capable of minimizing the problems set forth above.

Another purpose of the present invention lies in providing an automated steel section rolling control system for the manufacture of steel sections having target dimensions, by correcting the set value of reduction based on the standard pass schedule established for the following pass or the following stand. The foregoing is accomplished by making comparison between the dimensions 0f the respective parts-of a member to be rolled as measuredafter the initial pass and the values of the thickness of the web, the thickness of the flange, and the width of the flange, previously set as a target gage, in the steel section rolling process.

Still another purposeof the present invention lies in providing a control system that is capable of preparing the most suitable rolling pass schedule in a short period of time, by eliminating the expense of trial rolling and the possibility of an accident breaking down the manufacturing facilities both inherent in the trialand-error preparation of a rolling pass schedule that depends on the experience alone of an operator as set forth above.

Another purpose of the present invention lies in providing a system as described above that is capable of presuming the rolling temperature on the on-line basis in a quick and accurate manner, in case the surface temperature and the mean temperature of a member to be rolled are not equal to each other.

' Another purpose of the present invention lies in providing a system as described above that is capable of establishing the most suitable roll pass, by developing an approximate equation of width spread for the flange as well as an approximate equation of a rolling load, through establishment of the modified mechanism for establishing the roll pass for rolling of steel sections and byfurther devising approximate equations for the re covered value of the web and the decreased value of the web thickness, both constituting a problematical point peculiar to steel sections, then taking into consideration the value of the mill spring, the recovered value of the web, and/or the decreased value of the web thickness.

The present invention devised for attaining such purposes'as set forth above includes an automated steel section rolling control system, comprising a means of calculating the rolling temperature of a steel section, a means of preparing a pass schedule for the said steel section by making use of the rolling temperature thus calculated, a means of establishing a roll pass in each and every pass of said said steel section in pursuance to the said pass schedule, and a means of rolling the said steel section in the said roll pass thus established.

The present invention is specifically devised for the purpose of completely automating a steel section rolling process in the same manner as in the case of the plate rolling control; however, the plate rolling is different from the steel section rolling in many aspects, as far as the mechanism of the rolling mill is concerned, thus making it impractical to make use of the plate rolling control system for the steel section rolling. The features with regard. to the rolling of an H-steel section are roughly as set forth below.

in'contact with the roll are different from each other: the flange is reduced first, and then the web is drafted in the wake thereof. Therefore, the reduced area is divided into two sections.

Area I: The area in whichthe flange alone is reduced independently v Area ll: The area in which the web and the'flange are both reduced concurrently 2. The draft percentageof the web is different from that of the flange. Generally, the draft percentage of the flange is in excess of, or equal to, the draft percentage of the web.

.3. Metal flow occurs during drafting.

4. in the draft area i, the web presents a phenomenon of decrease in thickness. In this area, the web is not reduced by ,a horizontal roll, but the flange alone is reduced by a vertical roll. Therefore,.the web is subjected to the tensile force of the flange and is thus elongated, hence presenting the phenomenon of decreasein thickness.

5. In the draft area II, the web presents a phenomenon of recovery. At this time, the draft percentage of the web is generally greater than the draft percentage ofthe flange.v i h g h .6. The balance'of the rolling temperaturegenerated infill- 200C bet weeri theweb and the flange, and l 200C between the interior and the surface of each of the web and the flange.

As such, in the case of the roll control of the H- steel section, unlike the case of the plate control,

' the problem arises of what level of temperature to use.

In the present invention, the interior mean temperature is selected for the calculation of the rolling load and the roiling motive force. Meanwhile, in the case of checking whether or not the temperature thus measured is correct, in comparison with that measured by a thermometer, the surface temperature is selected for this purpose.

7. An H-steel section has the heatthereof insulated reciprocally between the web and the flange, and between one flange and the other flan ge,due to the geometrical shape thereof; therefore, it is imperative that these heat insulation effects be taken into consideration, for calculating the rolling temperature. I

. v l. The positions of the web and the flange to come- 8. In spite of the fact that the web and the flange are different'from eachother in the draft percentage thereof, the web and the flange areelongated as one'entity. Therefore, either one having a larger draft percentage is constrained by the other one having a smaller draft percentage, thus being subjected to the-compressibility thereof. The one having a smaller draft percentage is pulled toward the one having a larger draft percentage, thus being subjected to the tensile force thereof. Y Accordingly, the rolling loads of the horizontal roll and the vertical roll have to have the influence of this reciprocally operative force added thereto as i a tempering factor.

9. The motive power required for reel rolling is approximately three times as much as that required for ideal rolling, since the former is subjected to the considerable influence resulting from .the friction between a member to be rolled and theside surface I, of the horizontal roll, and also to the interior friction of the internal metal flow of the member to be rolled.

10. The width of the flange in rolling an H-steel section by a universal mill is extended or reduced, according to the reduction balance of. the flange and the web, unlike the case of the plate rolling.

As pointed out through the description given above,

in the rolling of an H-steelsection, the web and the flange have an influential interrelation with each other, thus resulting in a complicated rolling mechanism. The control system introduced in the present invention covers all of these various mechanisms, thus being capable of conducting the rolling of a steel section in a thoroughgoing and consolidated manner.

in the case of the present invention, the rolling control is completely automated mainly by the employment of model rolling temperature, a model motive power for rolling, a model condition for keeping the reduction balance, a model flange width spread, and a model rolling load. a

The model rolling temperature employed for the system of the present invention comprises the mean temperature of respective webs and flanges and the surface temperature. In this case, the mean temperature is em ployed for calculating the resistance of deformation, and the surface temperature is employed for making comparison of the actually measured temperature with the previously calculated'temperature.

The model motive power for rolling is that which is required for determining the distribution of the load of each mill and the elongation percentage ofthe entire section of each pass, including the web and the flange, in such a manner as to satisfy the following three points.

1. Rolling is conducted in the minimum frequencies of pass, and the balance of time between adjoining mills can be attained.

2. The final pass is subjected to a light load, thus ensuring the consistency of the quality.

3. Rolling is conducted within the limit of the speci fied length between the adjoining mills, respectively.

The condition of keeping thedraft balance is for the purpose of keeping the target thickness of the web and that of the flange on the most suitable level, thus preventing such harmful'problems as a web wave, a flange wave, and a flange width wave from occurring.

The model width spread of the flange is for the purpose of preventing a lack of uniformity in the width of the flange from taking shape, thus ensuring the design dimensions, and it is also employed for calculating the established value of the roll pass of an edger, as well as the target width of the flange. In addition thereto, the model width of the flange is employed for determining the position of a tilting table specifically designed for preventing offset of the web.

The model rolling load is specifically used to determine respectivepasses for the horizontal roll and the vertical roll for the purpose of securing the target thickness of the web and the target thickness of the flange, by taking into consideration such items as the rolling load, the mill rigidity coefficient, the decrease in value of the thickness of the web, and the recovered value of the web.

BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of the nature and the object of the present invention, reference is made to the following detailed description prepared in connection with the accompanying drawings, wherein:

FIG. 1 shows .a system diagram of the steel section rolling control system automated by the application of the present invention.

FIGS. 2a and 2b show a longitudinal section of plate steel and that of H-st'eel section, respectively.

FIG. 3 is a block diagram of the rolling temperature calculator for the system introduced in the present invention.

FIG. 4 is a block diagram showing virtually the entirety of the system introduced in the present invention in association with the pass schedule preparation device for rolling a steel section.

FIG. 5 is a traverse end view illustrating the shape of the top section of the flange drafted by an edging mill.

FIGS. 6a and b are graphs of the draft pattern: whereof (A) shows a general draft pattern, and (B) shows a standardized draft pattern.

FIG. 7 is a graph showing the relation between the horizontal roll pass at the time of rolling and the thickness of the web after rolling.

FIG. 8 is a graph showing the same'relationship as in FIG. 7.

FIGS. 9 and 10 are block diagramszshowing an outline of the system employed in an embodiment of the invention introduced herein.

FIG. 11 is an schematic block diagram of the calculating system introduced in the present invention.

FIG. 12 is a schematic'block diagram specifically showing the rolling control system of a hot rolling mill and the roll pass setting device of the same.

FIG. 13 is a graph prepared for the explanation of the corresponding relationship between deviation of the output gauge and the supplementary statement of the roll pass at the' subsequent pass or the subsequent stand. P

FIGS. 14(a) and (b) are schematic diagrams of the outline of the manifest universal mill and the edging mill, respectively.

FIG. 15 is a block diagram schematically showing the steel member rolling control system for ensuring the thickness most suitable control of rolling temperature.

FIG. 16 is a schematic diagram illustrating the nor- FIG. 18 is a block diagram schematically showing the steel member elongation control system.

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the system comprising the present invention will be described as a whole, then the system will be explained in detail item by item.

In FIG. 1, l is a water-cooled system, 2 is a temperature detector, 3 is a thickness detector, 4 is a width detector, 5 is a length detector, and 6 is a roll. These members are only schematically shown here, and it goes without saying that in actuality these members are actually constructed in a more complicated manner.

11 is an initial input device for the input of various conditions at the time of rolling. This initial input device ll is connected with a rolling temperature arithmetic unit 12 for a member to be rolled. The rolling temperature arithmetic unit 12 is connected with a pass schedule arithmetic unit 13 for the rolling of a steel section, and with a roll .pass setting device l4 for the rolling of a steel section connected with the said pass schedule arithmetic unit 13. A roll draft driving device 15 is set in place between the 'roll and the said roll 6. Y I

The system disclosed by thepresent invention has a steel member rolling control system 16, a thermometer position control system 17, a hot rolled steel section member rolling control system 18, and asteel member elongated length control system 19 arranged therefor for the purpose of further improving the rolling precison.

The detailed description of the respective systems set forth above isas given below.

The rolling temperature arithmetic unit 12 is so operated as to calculate the mean rolling temperature and the surface rolling temperature of the web and the flange, respectively, in the rolling of a steel section, by the real time.

The pass schedule arithmetic unit 13 is so operated as to prepare the most suitable arithmetic pass schedule for a steel section comprising rolling temperature, motive power for rolling, assumed respective model flange widths, and equationsof draft balance conditions.

The roll pass setting system 14 is so operated as to set a proper roll pass by the employment of an assumed model rolling load with the reciprocally functional power between the web and the flange taken into consideration, an assumed model web thickness with the decreased volume of the web thickness or the recovered value taken into consideration, and an assumed model flange width.

The steel member rolling control system 16 is so operated as to calculate the mean rolling temperature and the surface rolling temperature of the web and the flange, control the water cooled system I installed on the rolling line on the basis of the result of the said calculation, and thus control the temperature of a rolling mill.

The thermometer position control system 17 is so operated as to follow fluctuations in the dimensions of a steel member resulting from the progress of rolling in pass setting device 14 a 7 conformity with-the sizes for rolling, and thus control the position of the temperature detector 2 in such a manner as to enable the same position of a steel member to be measured at all time.

The hotrolled steel section member rolling control system 18 is so operated as to find deviations, if any, by way of the specified target dimensions for rolling and the actually measured dimensions by the employment of the thickness detector 3 and the width detector 4, calculate a correction value for the roll pass by the application of the specified related equation, and thus correct the roll pass for the subsequent pass.

The steel member elongated length control system 19 is so operated as to control the steel member elongated lengthto in advance within the allowable tolerance of the estimated sectional gauge in the rolling process in such a manner that the elongated length of a rolled steel member is not either in excess or less than the specified length in the case of cutting a steel member into several pieces of some certain specified dimensions in a sequential manner in the course of a hot rolling process. Y

Now, a description will be initial input system 11.

The initial input system 11 is what specifies, as shown in F IG. 4, the conditions of the facilities, including the rated output of the motor for each rolling mill, the allowable maximum load factor of each motor, the chargiven with regard to the acteristic value of each-motonthe limit condition of the use of the tables before and after rolling, and the dimensions of the roll employed for each rolling mill, such conditions as are established in view of the blooms, including the composition of a bloom an'dthe dimensions thereof, the number of aningot, the number of a bloom, the sequence of charge, and other conditions of actual operation, the conditions of rolling including the dimensional precision of finished product's, finished temperature, extraction temperature, quality control elongation and other quality control conditions, roll cooling conditions, conditions of descaling, conditions of cooling for temperature control, and such rolling temperature-as is actually measured by the employment of the thermometers installed in place along the rolling line at the time of the on-line use. The devices installed for-this purpose include an initial input setting panel, a tape reader, a card reader, and/or a superior computer.

Next, a description will be given with regard to the rolling temperature arithmetic unit 12 to be employed fora member to be'rolled.

An H-steel section comprises a web and two spacedly opposed flanges. The'heat radiation irradiated from a flange on one side, for instance, is incident upon the web or the flange on the other-side, thus resulting in transfer of heat between the flange and a web, as well as between flanges. A reciprocal heat insulating effect should also be taken into consideration. Furthermore, the plate 'under treatment is usually thick enough, thus rendering it rather improper to identify the surface temperature with the internal temperature. Suchbeing the situation, the present invention is aimed at developing such a new presumptive model as proves to be capable of calculating the mean temperature and the surface "temperature as well, thus being serviceable enough for finding the mean temperature and the sur-.

face temperature of the web and the flange, respectively, in each and every pass. The surface temperature can be measured by the employment of a thermometer, and a calculated value of the mean temperature can be properly corrected by the employment of the said value obtained through actual measurement. The motive power required for rolling can be calculated by the employment of the correct mean rolling temperature thus obtained.

In case the plate thickness of a steel member to be rolled is not thick enough, as in the case of rolling for finishing a hot strip, the surface temperature and the inner temperature are approximately equal to each other. However, in the case of rolling an H-steel section of substantial thickness in general, the balance of temperature between the mean temperature and the surface temperature is as much as 10 200C. Therefore, it was confirmed as a necessary step that the surface temperatureshould be found by actual measurement and calculation, beside the mean temperature thus calculated so that a calculated value was corrected in view of a value actually measured by the employment of a thermometer, or that whether or not the rolling temperature estimative equation was required to be subjected to a'proper judgment by the employment of a thermometer, and a value presumptive model duly capable of calculating the mean temperature and the surface temperature as well as the web as well as the flange was also successfully developed.

With regard to the present shown in FIGS. 2a and 2b, inventiomthe inventors confirmed to the effect that, in case the presumed mean rolling temperature of the steel member in the shape of either a plate or an l-l-steel section is taken as Tm, the presumed mean surface temperature of the said steel member is taken as Tf, the balance of the temperature between the said Tm and Tf is set to be ATs and the presumed meantemperature in the limited area shown byoblique lines and containing the symmetrical axes in-the section. In other words if, the specified standard sections (8,, S and S is taken as tm, the presumed surface temperature in the said limitedarea is taken as Tf, and the balance of the temperature between the said tm andts is presumed to be Ats, the following formula can be established.

This relation is likewise true for the web. The error in calculation to be as approximate as this is 14C at the most. Therefore, judging from this relation, the balance between the mean temperature and the surface temperature in the direction of the height of the web and in the direction of the width of the flange is prev in this case, Am is'such a characteristic number of the transcendental function satisfying theequation of Cot M k/hA, of which the answers are as many as infinite.

However, m 5 is deemed to be sufficient, as far as precision is concerned. [Boundary condition initial condition] K =f(x) (b)x=0; 6t/8x=0 (c) x =1; k8 (t ta)/8x h(t ta) 1- Time elapsed from the standard time x Distance from the center of the plate t Temperature 21 Thickness of the web f(x) Distribution of initial temperature h Heat-transfer coefficient k Heat conductivity ta Atmospheric temperature 2. Furthermore, the formula for the calculation of the balance between the mean temperature and the surface temperature in such a case that the thickness of the plate I fluctuates in a manner l= l 1 l,,, is as set forth below.

5 Ms 2 D(n,m) {sm )mm In awn) Mm 1n ii 3) 2 (Mt-11 7\ nm (while MP1]. l,, =)\nm In) 1 r 1 sin )mm In cos Mam In T 2 2Anm Pf Qf/Qfo 1.0 Qw0-l, -e/Qf0 1 's (5) I Here, Qwo, Qfo Quantities of radiant heat by the web and the flange in the case of total radiation Ow, Qf True quantities of radiant heat by the web and the flange 1'12. P Effective form coefficient between the flanges and between the flange and web 6: Emissibility Aw. Af Surface areas of the web and the flange Now. a detail description will be given below with regard to the rolling temperature calculating system 12. In FIG. 3, 101 is a rolling condition setting system, 101a is a unit for setting such different physical constants as the specific heat of a member to be rolled, the

specific gravity of the member to be rolled, the Stephan-Boltzmanns constants, the thermal conductivities of the web and the flange, emissibility, and the weight of a member to be rolled. 10lb is a unit for setting the scheduled lapse of time for rolling, 1010 is a unit for setting the dimensions of a member to be rolled, 101d is a unit for setting the quantity of rool cooling water, 101:: is a unit for setting the quantity of descaling water, and 101]" is a unit for setting the anticipated value of the quantity of heat generated by working. 102 is a detector of the temperature of a rolled member at the time of the extraction thereof, and contains a unit that detects a rolled member 103 being extracted. 104 is a thermometer for actually measuring the surface temperature of a rolled member, and contains a unit that'detects a rolled member 105 arriving at the specified position. 106 is a calculator of the anticipated mean rolling temperature of a rolled member,

107 is a standard section anticipated temperature calculator for calculating the anticipated surface temperature and the anticipated mean temperature of the specified standard section and the balance of temperature between such, and 108 is an anticipated surface temperature calculating unit for calculating the anticipated mean surface temperature by means of an input signal transmitted by the said mean rolling temperature calculating unit 106 and an input signal transmitted by the said standard section anticipated temperature calculating unit 107. 109 is a corrected temperature calculating unit for calculating the corrected anticipated mean rolling temperature by taking as the criteria therefor an input signal generated by the said actually measured temperature detecting unit 104 and an input signal generated by the said anticipated surface temperature calculating unit 108. In other words, by means of the anticipated mean rolling temperature signal and the anticipated surface temperature signal 110 is a rolling control calculation order unit for giving an order to respective rolling control units by receiving the said corrected anticipated mean rolling temperature signal.

Here, a description will be given with regard to the outline of the action of the aforementioned units. When information as to rolling conditions provided by the said rolling condition setting unit 101, including respective physical constants, anticipated time required for rolling, dimensions of a member to be rolled, quantity of roll'cooling water, quantity of descaling water, estimated value of the quantity of heat generated in the course of working, and weight of a member to be rolled, and fed to the estimated mean rollingtemperature arithmetic unit 106 and the standard section estimated temperature arithmetic unit 107, and a rolled member is concurrently extracted from a heating fur nace or an ignition furnace, of which the drawing is not given herein, extraction temperature of the rolled member is put in to the estimated mean rolling temperature arithmetic unit 106 from the rolled member temperature detecting unit 102 by the action of the extraction detecting unit 103. When the rolled member further arrives at the specified position of the rolling line, actually measured surface temperature is likewise put into the estimated mean rolling temperature calculating unit 106 from the actually measured rolled member surface temperature detecting unit 104 at that time by virtue of the arrival detecting unit (a detecting unit for HMD or the like, for instance) 105, and presumptive calculation of the estimated mean rolling temperature Tm is conducted there. Then, signals with regard'to the frequency of pass, the surface area of a rolled member, and a transformation coefficient are put into the estimated standard section temperature calculating unit 107 from the presumed mean rolling temperature calculating unit 106. Next, the said presumed mean rolling temperature Tm and the said balance of temperature ATs are put into the presumed surface temperature cal culating unit 108, whereby the presumed mean surface temperature Tf of a rolled member is found.

The actually measured surface temperature Tfo transmitted from the actually measured temperature detectorl04 and the said presumed mean surfacetemperature Tf are put into the temperature correcting and calculating unit I00,v wherein the balance between the both temperatures ATf Tfo TI) is calculated. Then an input signal from the presumed mean rolling temperature arithmetic unit 106, that is to say, the anticipated mean rolling temperature Tm is corrected and calculated by the application of the following formula:.

to identify different rolling process control system,

namely, a rolling control calculation order unit 110, thus making the most thereof as a piece of important standard information, rolling efficiency can be improved and better quality can be promoted.

203 is a unitfor calculating the motive power required for rolling, included in a pass schedule preparation unit 13, and it calculates the frequency of the pass of each roller, the elongated ratio of each pass, and the frequency of revolution of theuniversal horizontal roll by soselecting the elongationlength limit condition, the elongation condition quality limit, and thedesignated load factor as to be capableof o keeping proper balance of time among respective mills in the case of reverse rolling by two or more tandem engines and at the minimum pass frequ yi 1 i f conducting light-load operation by setting the forming pass for approximately 2 3 passes at the final stageof rolling, thus ensuring consistency of quality, and

conducting rolling within the limit to the elongation length at the front'and the rear of each mill due to the nature of the equipment, by the employment of the assumed rolling motive power model, on the basis of the input signals of the equipment condition, the bloom condition, and the rolling condition transmitted from the said initial input unit II and the input signal of the rolling temperature transmitted from the said rolling temperature calculating unit 12.

The elongation ratio is found by the application'of the following formula: Q Elongation ratio (Sectional area of rolled member before rolling)/(Sectional area of rolled member after rolling) i In the rolling of a plate, the relation between the motive power required for rolling and the elongation ratio has been already elucidated by the HHT curve. However, in the rolling of an H-steel section, the said formula for assuming the motive power required for rolling already developed in rolling of a plate proves inapplicable thereto, due to such differences existing between I-l-steel section rolling and plate rolling, that o the web section and the flange section are different from each other in draft percentage, thus resulting in reciprocal functioning of the compressive force and the tensile force between the web section and the flange section, 0 the web section and the flange section are different from each other in rolling temperature, and 0 the horizontal roll and'the vertical roll of the universal mill are different from each other in direction of revolution, and the vertical roll is drive-free.

The main function of the model rolling motive power lies in the determination of the total elongation ratio, including the web and the flange, capable of rolling under the maximum allowable operation torque of a rolling motor given thereto. In case deformation in rolling' is assumed to be under way under an ideal state of stress of one shaft, the quantity of work W required for this deformation; is expressed as follows:

w= stave-m7, [kW-S] Here, kt Effective deformation resistance [kg/mm] (mean effective resistance of quadratic restriction plus internal friction, external'friction, motor loss and deformation: resistance conversion value of mechanical loss and so forth) V Volume of rolled member mm 1 Elongation ratio I In the formula (6), it proved successful to find the effective deformation resistance k1, thus formulating it, by conducting actual measurement of the values of W, V and 1 v kt 0.92 exp (0.5/t 0.0l/C 0.05) (2,32 t-l generally have a value different from the total value of Here, r= T 273 1,000

elongation ratio Awn, flange thickness total elongation ratio )tfn and flange width total elongation ratio Mm all the said elongation ratios. However, it has been confirmed by experimentation data that proper balance between the draft of the web and the draft of the flange can be kept by conforming the draft patterns of the web thickness, the flange thickness and the flange width, re-

spectively,'with the draft pattern of the total elongation ratio. To put it otherwise, favorable rolling is enabled by the proper determination of )twi, M1 and )thi in such a manneras to satisfy the following equation.

Furthermore, the thickness of the web of a member to be rolled will be properly modified, prior to rolling, in the direction of thinning, in the case of I The said thickness will be properly modified, prior to rolling, in the direction of thickening, in the case of Now, a description with regard to the calculating unit 13 willbe given below.

The pass schedule calculating unit 13 is what determines to what degree the web thickness, the flange thickness and the flange width should be drafted, respectively, in the wake of finding the elongation ratio of a member to be rolled, with the web and the flange taken together. As set forth above, an H-steel section and a steel plate comprise a web section and a flange section but in a different manner, and because the web section and the flange section are both subjected to rolling by different draft percentages both should be elongated as one entity, whereas some certain restrictive condition is established naturally enough between the draft percentages of the web section and the flange section. In the present invention, the said restrictive condition is called adraft balance condition.

In casesome deviation from the said draft balance condition should be present, such quite harmful effects as defective shapes like waves of the web and waves of the flange, and deviation from the established specifications including excess or shortage in the width of the flange are thereby possible. Therefore the draft percentage of the web thickness, the draft percentage of the flange thickness, and the draft percentage of the flange width should all be such that the said draft balance condition is satisfied. With regard to the flange width among others, reduction in the web thickness and/or the flange thickness in the universal mill results in fluctuations in the flange width as well. Therefore, it is quite important a matter that such fluctuations in the flange width be anticipated with utmost precision for obtaining finished products featuring precise dimensions of the flange width and a regular top shape of the flange, as well as for determining such a flange width pass schedule draft percentage as satisfies the said draft balance condition. However, the fluctuations in the flange width in the case of a universal mill involves the difficult problem of to what degree such a flange that has had the top reduced in dimension through rolling by an edger, beside fluctuations in the width of the flange resulting from reduction in dimension of the web and the flange, until it assumes such a shape as is shown in FIG. 5, can have the width of the said flange properly restituted. In other words, to what degree the width of the flange is subjected'to reduction through rolling by'- the edger in actual process, should be properly accounted for. Such an accounting has never been made thus far with regard to the fluctuations in the width of the flange.

Such being the situation, reduction in the width of the flange was conducted on the trial-and-error basis simply relying on experiences and intuition. The key matter of how much used to be the quantity of reduction in the width of a flange in the actual process of rollingin an edging mill was left out of consideration, whereby whether or not the reduction balance condi tion was satisfied could not be checked. Rolling was conducted under such a state that the width of a finished product could not even be anticipated at all. The

inventors in the present application developed such formulas for assuming the fluctuations in the width of the flange as set forth below, for the purpose of solving problems.

First, in the case of rolling by the employment only of a universal mill, it was determined that fluctuations in the width of a flange AFh, increase in proportion to reduction in the thickness of the flange AF! and decrease in proportion to reduction in the thickness of a web AWt. In addition thereto it was determined that fluctuations in the width of a flange could be assumed with quite high precision by setting such a flange width spread coefficient C, that could be found by the application of the equation set forth below.

AFI 1,'= C AF: AW:

Then, in the case of rolling by the employment of a universal mill an I-I-steel section of such'a shape as shown in FIG. 5 at the rate of 0 of the quantity of reduction in the thickness of theweb and the flange, in the wake of reduction in the dimension of the'top of the flange by the employment of an edging mill, it was learned that the fluctuations in thewidth of the flange AFh were such as were found by the application of the following equatiomthrough experimental data.'

Now, explanation of the outline of transmission and reception of a signal among the said rolling temperature calculating unit 12, the rolling motive power requirement calculating unit 203, and the pass schedule it can be calculated as well on the basis of estimated 15 time covering the span from the time of actually measuring the surface temperature to the time of starting rolling by the employment of a universal mill. The rolling temperature can also be calculated on the basis of the dimensions of a member to be rolled in the wake of rolling in the pass and the actually measured value-of the surface temperature inthe wake of the completion of rolling in the pass, in case grooved rolling in such a I pass is to be conducted prior to starting the saidunivertion ratio thus calculated with the web section and the V flange section taken together therein. And rise in temperature'of a rolled member resulting from the rolling work is to be found by the employment of the rolling temperature calculating unit 12 on the basis of the rolling motive power requirement already found by the employment of the said rolling motive power requirement by calculating unit 203,and calculation of the rolling temperature before the rolling in th'e'second pass 'on the basis of the dimensions ofthe rolled member already found by the employment of the pass schedule calculating unit 13. The rolling temperatures (including the mean and surface temperatures of the web and the flange) of a member to be. rolled in each pass, the rolling motivepo'wer-requirement, and the rolling pass schedule can be found by repeating the said processes in aregular sequential manner. The system introduced in the present invention makes it practicable to conduct calculation even in the middle of'rolling by feeding the rolling temperature calculating unit 12 with the actually measured surface temperatures of the web section and the flange section in such midpoint of rolling. It is also practical to find the rolling temperatures (including the mean and surface temperatures of the web and the flange.) of themember under rolling in respective passes, the motive power required for rolling, and the rolling pass schedule after such midpoint of rolling. The output transmitted from the pass schedule calculating unit 1-3 becomes an i'n'putsignal to the roll position calculating unit 205 at the time of on-line operation. The setup value of the roll is calculated here with the quantity of mill spring and so forth taken into consideration, and the result of this calculation be comes'the input signal to the roll position control system207.-

At the time of off-line operation, the outputs from the pass schedule calculating unit 13 and the roll position calculating unit 205 are to be utilized as required, after they have been fed to indicators 206 for example, a line printer.

Next, explanation-will be given hereinafter with regard to the roll passsetting unit 14. The draft percentage of the web section differs from that of the flange section even in the area ll in which both the, web section and the flange-section are subjected to draft or reduction. Due to the difference in the draft percentage, the same reciprocally functioning power in the reduction areal functions in the reduction area ll as well. Results of investigation of the effects exercised by this reciprocally functioning power on the thickness of the web and the thickness of the flange at the time of rolling have been found to be such shown in FIG. 7 and H6. 8, through experiments specifically conducted with regard to rolling of model plasticine. FIG. 7 shows the relation between the actually measured value of the horizontal roll pass, S'h (horizontal axis), in the course of rolling and the thickness of the web, Wt (axis of ordinate), after rolling, in the case of rolling under the condition ofthe draft percentage of the web the draft percentage of the flange in the area of concurrent reduction in the dimensions of the web and the flange. Here, S'h is expressed as set forth below;

S'h= Sh AH Sh: Set point of horizontal roll pass 7 AH: Quantity of mill spring In this case, as shown in FIG. 7, the following relation is learned; the of the web after rolling actually measured value of the horizontal roll pass.

.To put it otherwise, the web has recovered the thick- FIG. 8 shows the relation between the actually measured valuefof the horizontal roll pass S'l-l (horizontal axis) in the course of rolling and the thickness of the web Wt (axis of ordinate) after the rolling in the case of rolling under such a condition as Draft percentage of the flange 2 draft percentage of the web in the area of concurrent reduction in the dimensions of the web and the flange. ln this case, the relation is learned to be thickness of the web after rolling 5 actually measured value of horizontal roll' pass. v

To put it otherwise, the thickness of the web is slightly thinner than the. actually measured value of the horizontal roll pass. Such a phenomenon asthis will be called reduction in thickness of'a'web.

It has been confirmed that such phenomena as the restitution of the web and the reduction in thickness of the web set forth above are what take shape in exactly the same manner in the case of actual rolling of steel members as well.

In the case of rolling of an H-steel section by the employment of a universal mill, such a phenomenon as the restitution of the web or the reduction in thickness of the web takes shape under the condition of rolling in the reduction area ll as set forth above. The thickness of the web after rolling is difi'erent in value from the roll pass when rollingis actually under way with the set point of the roll pass. and the-quantity of the mill spring due to rolling load taken intoconsideration. The thickness of the web after rolling with such a matter peculiar to the rolling of an'H-ste el section as the restitution of the web or the reduction in thickness of the web'duly taken into consideration can be presumed by solving such equations as set forth below. Model rolling load 1.. Relations of dimensions in the reduction area I and thereduction area ll 17 1. Relations between unknown quantities and equations in the reduction area I are as set forthbelow.

A. Geometrical relations of mass flow constants in the reduction area I (Z-Fn-Fh, Wt,-U)/ (2-Ft -Fh wz -u) B. Equation of relation to be found due to the fact that the projection contact lengths of the web and the flange from the output side of the roll are equal to each other in the reduction area [I C. Equation for presuming the expansion of the width of the flange in the reduction area I Fh Fh, c (Ft F12) (Wt W1 C2-AE D. Equation for presuming the total elongation at, on the basis of the principle of a presumed work A. Geometrical relations of mass flow constants in the reduction area ll B. Equation for presuming the expansion of the width of the flange in the reduction area ll F11, =Fh C (F12 F13) (Wt, W13) C Equation for presuming the total elongation m on the basis of the principle of a presumed work Explanation of symbols Wr, Fl, Fh: Web thickness, flange thickness, flange width Suffix 1: Before rolling Suffix 2: Starting position in the area ll Suffix 3: After rolling SH, Sv: Horizontal roll pass, vertical roll pass kw: Web deformation resistance Irf: Flange deformation resistance Vw Vf,: Volume of the web (one side) and volume of the flange (one side) before rolling Vw Vf Volume of the web (one side) and volume' of the flange (one side) when in area Il RH: Radius of the horizontal roll Rv: Equivalent radius of the vertical roll 2. Rolling load 1. Rolling load in the reduction area I I Wherein, Q is the flange constraint coefficient in the reduction area i, and the volume of work required for reducing'only the dimensions of the flange under the unified state of the flange and the web is as much as Qf times that required in the case of reducing the dimensions of the flange alone in a separate manner.

2. Rolling load in the reduction area ll Wherein, Qw is the web constraint coefficient in the reduction area H, the web is constrained by the difference in elongation of the web and the flange, and the energy required therefor is as much as Qw times that required in the case of elongating the web as a single unit.

3. Rolling load by the restitution of the web PH kw'U'Lw /2 (37) 4. Effect of the rolling load of the vertical roll exercised on the rolling load of the horizontal roll by the edge taper of the horizontal roll PH PV'tan a r '5. Effect of the edge fric tion componentforce of the horizontal roll exercised on the rolling load of the horizontal roll 7 v ,,p,, Fe Lt v PH L L cos sam m. (39) 40 6. Equations of the rolling load E PH PH PH PH PH, PH

(Qgw-QwLw Lw /2)kw'U+ (P-pt tan a)PV 7Z6 5 PV, PV; Qgf'kflQf-Fh, (Lf & Lf fzl (4|) of the AFh C -AFt AW:

Lw Length of projection contact of the web in the wherein,

C Flange width spread coefficient AFt; Reduction in the dimensions of the flange AWt: Reduction in the dimensions of the web -2. Presumption of the flange width restitution AFh after reduction thereof by the edger and the vertical roll with the quantity of mill springby rolling load and the restitution of the web or reduction in the thickness of the web constituting a problematical point peculiar to the rolling of an H-steel section. Unit 14 also functions to calculate the set position for; the edger roll pass for the purpose of securing proper width ofa flow chart is-as shown in FIG. 11.

In FIG. 11, 307 shows information furnished by the initial input 'unit 11 including the target rolling thickness of the web and the flange (Wri, Fti) in each pass, the targetrolling width of the flange (Fhi), and the diof the flangeJTheoutline of the calculation in the form mensions of the roll. 308 shows the input information furnished by the rolling temperature arithmetic unit 12 including'rolling temperature of the 'web section and the flangesection in each pass. 309 conducts the calculation of the set position in the roll pass for the edger.

t 310 is the presumed passes of the horizontal roll and the vertical roll. (With regard to the thickness of the flange, no restitution is deemed to take shape, hence,

the vertical roll pass target rolling thickness of the fl e I i a i 311 shows the function of conducting the calculation of the presumedthickness'of the-web W'ti after rolling and the calculation of deformation resistance and transformation coefficients of the web and the flange. 312 is the comparative function unit for the said W'ti and Wu, and makes correction of a presumed horizontal roll pass by turning back to the said 310 in the case of Wn' Will-It advances to 313 in the case of Wti Wu. Unit 313 conducts calculation of the rolling load for the vertical roll.'314 conducts calculation of effectsof the rolling-load of the vertical roll exercised on the rolling load of the horizontal roll. 315 conducts calculation of the rolling load of the horizontalroll. 316

- conducts calculation" of the rigidity coefficient of the mill. 317 conducts calculation of the mill spring. 318 shows the function of calculation of the set position for the roll pass. 304 is a roll position setting, unit and has such a function as to set respective roll-positions on the basis of the set positionsof the roll'passes for the horizontal roll, thevertical roll and the edger roll found by the roll pass arithmetic unit 303.

Byrnaking proper combination of such respective units as are set forth above in a manner shown'in FIG.

9, the most suitable setting of thepasses for the universal roll and the edger roll can be effectuated. So also the most suitable setting positions for the universal roll and the edger roll can be calculated on the on-line ba- SIS. t

In FIG. 10, 305 is an input unit, and puts in different information by way of either a card reader ora tape reader in the same manneras in the case of the initial input unit 301 shown in FIG. 9. Furthermore, 12 is a rolling temperature calculating unit, and 306 is aroll pass indicator which feeds either a line printer or a typewriter with the result ofcalculation found as an output by a roll pass calculating unit 303. In case the information thus obtained is utilized for rolling or em-- ployed for the analysis of rolling in an expedient manner as occasions arise, such can be made available for pertinent uses in a quite extensive range, thus having the value thereof for practical purposes enhanced a great deal.

In, the present invention, in case the roll position setting unit 304 is not employed for the on-line operation, the roll pass indicator 306 alone may well be employed in its place. Fu'rthermore, it shouldbe understood that when only the roll position setting unit 304 is put in operation as-required by the practical case or the roll position setting unit 304 and the roll pass indicator 306 are both put in operation concurrently it'is within the scope of this invention. Recommended for the use of the roll pass indicator304 for this purpose is'either a punched tape or a magnetic tape." Y 1 Next,'a description will be given hereinafter with re gard to the rolling control unit l8'that improves the precision of the reduction in the dimensions of the rollby supplementing the roll pass setting unit 14.

FIG. 12 is a block diagram of one embodimentof the present invention, wherein 405 is a horizontal roll pass input device forputting inthe' horizontal roll pass for each pass of the standard pass schedule established for each size of rolling. 406 is a vertical roll pass input device, and 407 is an edging roll pass input device. 420 isa horizontal roll positioning control unit that has the horizonatal roll 403 conduct positioningcontrol in the roll-pass furnished in advance, by way of a horizontal roll reducing and driving unit 423. The vertical roll 402 as well as the edging roll 404 has the position thereof controlled by 'a-vertical' roll positioning control unit 421, a vertical roll reducing and driving unit 424, an edging roll positioningc'ontrol unit 422, and/or an edging roll reducing and driving unit 425. P

426 is a webthickness detector, 427 is a flange thickness detector, and 428 is a flange width detector. The

output gauge of each section of a rolled member at the time of completion of each rolling pass or after passage through each rolling stand is measured by the employment of these detectors. In the wake thereof, the values thus actually measured and respective target values fed by the target web thickness value input device 408, the

target flange thickness value input device 409, and the target flange width value input device-are fedas an input into a web thickness deviation arithmetic 411, a flange thickness deviation arithmetic 412, and a flange width deviation arithmetic 413, respectivelyLFurthermore, 414 is a horizontal roll pass correction limit value calculatingunit, 415 is a vertical roll pass correction limit valuecalculating unit, and 416 is an edging roll pass vcorrectionlim'it value calculating unit. These calculating units are are. specifically/installed so that the correction of the roll pass is restricted and does not exceed a limit over some certain value in such an area in which the deviation of the output gage is in excess of a certain range, in order to keep the balance of elongation of respective sections. 417 is ahorizontal roll pass correcting and calculating unit, 418 is a vertical roll pass correcting and calculating unit, and 419 is an edging roll pass correcting and calculating unit. These units conduct calculation for correcting respective roll passes for the subsequent pass or the subsequent stand by way of respective input signals received from the said web thickness calculating unit 411, the flange thickness calculating unit 412, and the flange width calculating unit 413. The output signals are transmitted to a horizontal roll positioning control unit 420, a vertical roll positioning control unit 421, and an edging roll positioning control unit 422, respectively. In this case, the correction is subjected to a certain limit as set forth above. Wherein the horizontal roll pass correction limit value calculating unit 414 conducts calculation of the area in which the web can be corrected independently by taking as the criteria therefor the deviation in the flange thickness of the said pass or the said stand to be calculated by the flange thickness deviation calculating unit 412 from the values measured by the target flange thickness setting unit 409 and the flange thickness detecting unit 427 arranged in the said'pass or the said stand, and the target web thickness value in the subsequent pass already set by the target web thickness setting unit 408, thus controlling the proportional area of the horizontal roll pass correcting and calculating unit 417, and has the vertical roll pass limit value calculating unit 415 likewise control the proportional area of the vertical roll pass correcting and calculating unit 418 by taking as an input the target flange thickness of the subsequent pass or the subsequent stand as well as the output of deviation of the web thickness deviation calculating unit 411 in the said pass or on the said stand for the purpose of reflecting a reciprocal function on the flange by correcting the web. The edging roll pass correction limit value calculating unit 416 is also so constituted as to have virtually the same functions as the said roll pass correction limit value calculating unit 414 and the vertical roll pass correction limit value calculating unit 415, and in the case of the illustration introduced in the present invention, the edging roll pass correcting and calculating unit 419 is so constituted as to have the proportional section thereof controlled only by the target flange width of the subsequent pass or the subsequent stand. However, the said unit 419 may well be so constituted as to controlthe said proportional section in consideration of its association with each thickness deviation.

,Now, hereinafter given will be an explanation of the outline of the manifest universal roll and edging roll employed for hot rolling of an H-steel section shown in FIGS. 14a and 14b. in these two Figures, 401 is a'mem- .ber to be rolled, 403 is a horizontal roll that maintains the height and the thickness of the web to be in conformity with the target values, and maintains the thickness of the flange and connecting joints of the web and the flange in a regular manner by properly controlling the roll pass between .the vertical rolls 402, and 404 is an edging roll for which the purposeis to maintain the edging and the width of the flange.

Next, given will bean explanation with regard to the steel member rolling control unit 16.

in FIG. 15, 501 is a rolling condition setting unit 5010 is a section for setting respective physical constants, for instance, specific heat of a member to be rolled, specific gravity of a member to be rolled, the Stefan- Boltzmanns constant, thermal conductivityof the web and the flange, respectively, emissivity, and weight of a member to be rolled. 501b is a section for setting estimated rolling time lapse, 5016 is a section for setting dimensions of a member to be rolled, 501d is a section for setting the quantity of roll cooling water, 501e is a section for setting the quantity of descaling water, and 1 f is a section for setting an estimated value of calory generated in the course of working. 502 is a rolled member temperature detecting unit to be employed at the time of extraction, which includes a unit 503 for detecting that a rolled member has been extracted. 504 is a temperature detector for actually measuring the surface temperature of a rolled member, and includes a unit 505 for detecting the arrival of a rolled member at a specified position. 506 is an estimated mean rolling temperature calculating unit for a member to be rolled, 507 is a standard section temperature calculating unit for calculating estimated surface temperature and estimated mean temperature of a specified standard section and the balance of the both tempertures, and 508 is an estimated surface temperature calculating unit for calculating the estimated mean surface temperature of a member under rolling byan input signal transmitted by the estimated mean rolling temperature calculating unit 506'and an'input signal transmitted by the estimated standard section temperature calculating unit 507. 509 is a temperature correcting and-calculating unit for conducting correction and calculation of an estimated mean rolling temperature by means of an input signal transmitted by an actually measured temperature detecting unit 504 and an input signal transmitted by the said estimated surface temperature calculating unit 508. In other words, by'means of an estimated mean rolling temperature signal and an estimated mean surface temperature signal. 510 is a reduced screw position setting unit, 511 is a target steel member rolling temperature ordering unit, 512 is a cooling control unit including therein the said target steel member rolling temperature ordering unit 511 and comprising a steel member cooling unit value timing gear and a wet time setting unit. 513 is a roll, 514 is a reduction drive unit of a rolling mill, 515 is a cooling water quantity control valve, and 516 is a cooling unit comprising a cooling water tank, a nozzle and so forth. Now, an outline of the action of the aforementioned'units will be-explained below; When information of rolling conditions fed by the rolling condition setting unit 501, including respective physical constants, estimated rolling time requirement, dimensions of a member to be rolled, quantity of roll cooling water, quantity of descaling water, estimated value of calory to be generated in the course of working, and weight of the member to be rolled are fed as an input into the estimated mean rolling temperature calculating unit 506 and the estimated standard section temperature calculating unit 507, and a rolled member is concurrently extracted out of a heating pit or a soaking pit, which is not shown in the drawings, extraction temperature of the rolled member is fed as an input into the estimated mean rolling temperature calculating unit 506 from the temperature detecti'ng unit 502 by the action of the extraction detect ing unit 503. And when the rolled member further ar- 

1. An automated steel section rolling control system comprising a rolling temperature calculating unit for calculating the rolling temperature of a steel section, said unit computing the estimated mean temperature and the estimated surface temperature of said steel section to obtain the corrected mean temperature thereof, means for preparing a pass schedule for said steel section by the employment of the rolling temperature thus calculated, means for setting a roll pass in each pass for said steel section in pursuance to said pass schedule, and means for rolling said steel section in said roll pass thus set.
 2. The automated steel section rolling control system set forth in claim 1, in which said rolling temperature calculating unit comprises: a unit for calculating the estimated mean rolling temperature of a member to be rolled, by way of a rolling condition input signal transmitted by a rolling condition setting unit and an input signal transmitted by a rolled member temperature detecting unit at the time of extraction of the rolled member; an estimated standard section temperature calculating unit for calculating an estimated surface temperature of the rolled member, an estimated meAn temperature of the rolled member and the difference between these temperatures by way of input signals transmitted by both said rolling condition setting unit and said estimated mean rolling temperature calcualting unit; a unit for calculating the estimated surface temperature of the rolled member by way of input signals transmitted by both said estimated mean rolling temperature calculating unit and the estimated standard section temperature calculating unit; and a temperature correcting and calculating unit for finding the temperature difference between an actually measured surface temperature and an estimated surface temperature by way of input signals which are transmitted by a thermometer for actually measuring the surface temperature at the time of arrival of a rolled member at a predetermined position and transmitted by said estimated surface temperature calculating unit, thereby correcting and calculating the estimated mean rolling temperature input signal on the basis of said temperature difference.
 3. The automated steel section rolling control system set forth in claim 1, in which said means for preparing said pass schedule is a pass schedule preparing unit for a steel section which includes a rolling temperature model, a rolling motive power, a flange width spread model, and reduction balance condition.
 4. The automated steel section rolling control system set forth in claim 3, in which said pass schedule preparing unit comprises: a rolling motive power requirement calculating unit for calculating and determining pass distribution to respective rolling mills, the elongation ratio in each pass and the speed of a horizontal roll; and a pass schedule calculating unit for calculating such a pass schedule as satisfies the reduction balance condition in each pass on the basis of the reduction balance condition, the flange width spread model and an input signal transmitted by the said rolling motive power requirement calculating unit.
 5. The automated steel section rolling control system set forth in claim 1, in which said means of setting said rolling roll pass is a roll pass setting unit which comprises three models consisting of a presumptive rolling load model with reciprocally working force between the web and the flange of said steel section taken into consideration, a presumptive web thickness model with reduction in web thickness, and a resumptive flange width model.
 6. The automated steel section rolling control system set forth in claim 5, in which said roll pass setting unit comprises: a roll pass calculating unit for calculating each setting point of a horizontal roll, a vertical roll and an edger roll in respective passes, on the basis of presumptive web thickness model after rolling, presumptive flange width spread model, and an input signal from said means for calculating the rolling temperature; and a roll pass indicating unit for indicating respective roll passes of the horizontal roll, the vertical roll and the edger roll in respective passes on the basis of the input signals transmitted by the roll position setting unit for setting the roll positions of the horizontal, vertical and edger rolls by way of the input signals transmitted by said roll pass calculating unit and on the basis of input signals transmitted by said roll pass calculating unit.
 7. The automated steel section rolling control system set forth in claim 1, the system comprising further a unit for setting the target output gauge of said steel section and a unit for actually measuring and detecting the gauges of said steel section, the deviation signals from a deviation arithmetic obtained by feeding said deviation arithmetic with the actually measured value transmitted by said detecting unit as well as the target output gauge transmitted by said setting unit as the inputs therefor being fed as inputs into a roll pass correcting and calculating unit; a reduction set value on the standard pass schedule of the reduction positioning control unit being corrected by an outpuT signal transmitted by said roll pass correcting and calculating unit, whereby the output gauge of a rolled member in the subsequent pass and on the subsequent stand may be properly corrected.
 8. An automated steel section rolling control system comprising means for calculating temperatures in different portions of a steel section which are placed under different rolling conditions; means for programming a pass schedule for said steel section in accordance with the thus calculated temperatures in consideration of the reduction balance between said different portions; means for setting a roll clearance in each pass in pursuance to said pass schedule; and means for rolling said steel section in the thus set roll clearance.
 9. The automated steel section rolling control system set forth in claim 8, wherein said means for calculating temperatures comprises a rolling temperature calculating unit which computes the estimated mean temperature and the estimated surface temperature of said steel section to obtain a corrected mean temperature on the basis of the difference between the estimated surface temperature and an actually measured surface temperature of said steel section.
 10. The automated steel section rolling control system set forth in claim 1, wherein said steel section is an H-shaped steel section. 